Metabones Canon EF to RF Speed Booster ULTRA 0.71x

Metabones EF-RF Speed Booster® ULTRA 0.71x - to adapt Canon EF mount full-frame lenses to the new Canon RF mount. Users are now able to mitigate most of the APS-C crop factor of EOS R7/R10 (1.60x) and EOS C70 (1.45x) and reduce it to 1.14x and 1.03x respectively and support the RED KOMODO 6K Cinema Camera(Super 35mm sensor). The field of view is now much closer to the full-frame look. On the full-frame camera like EOS R5. R5c, R3, this Speed Booster is not intended for still photography but will work if the camera is configured to APS-C mode, and will work well with the specific video crop modes. For details of the crop factor by the camera and mode, please refer to the following table.

Speed Booster ULTRA uses an advanced 5-element/4-group optical design by Caldwell Photographic Inc., incorporating ultra-high index tantalum-based optical glass to achieve extraordinary optical performance with improved corner sharpness, distortion and reduced vignetting. Speed Booster ULTRA has a magnification of 0.71x, effectively reducing the crop factor of 4k video on EOS R and EOS RP from 1.75x to 1.24x. The Speed Booster ULTRA design makes very effective use of exotic materials at the furthest limit of glassmaking technology, and as a result is well corrected for use with virtually all full-frame SLR lenses regardless of exit pupil distance. Thus, the Speed Booster ULTRA performs extremely well with professional-grade f/2.8 zoom lenses such as the 24-70mm f/2.8 and 70-200mm f/2.8 zooms by Canon to produce 17-50mm f/2.0 and 50-142mm f/2.0 high-speed zooms, respectively. Similarly, high-speed fixed focal length lenses such as a 50mm f/1.2 will be transformed into a 35.5mm f/0.9 lens with excellent contrast and resolution from the center all the way to the edges of the image. (More information can be found in the press release here)